Adapter for a &#34;smith-peterson&#34; nail



J1me 195'1 v A. s. LLOYD 69 ADAPTER FOR A "SMITH-PETERSON" NAIL Filed July 2'7, 1950 INVENT OR "j/ /e n j 'LL'o d ATTORNEY Patented June 19, 1951 UNITED STATES PATENT OFFICE ADAPTER FOR A SMITH-PETERSON NAIL Allen S. Lloyd, Washington, D. 0.

Application July27, 1950, Serial No. 176,200

Claims. (Cl. 12892) The present invention relates to surgical devices and has reference more particularly to a device for the purpose of internal fixation of a fracture of the neck of the femur.

A cannulated or non-cannulated nail, known as a Smith-Peterson nail is commonly used in connection with the internal fixation of fractures of the neck of the femur.

. These Smith-Peterson nails are made in various lengths. Many methods have been devised by .the orthopedic surgeon to determine which length nailis to be selected in the particular case undergoing treatment.

,None of the methods thus far known have proven satisfactory, since the fragments sometimes impact during insertion of the nail, and also, frequently the nail slides upward during penetration of the cortex, thus changing the point of entrance and consequently changing the length required to penetrate the head of the femur to the proper distance.

' If the length of nail selected is too long, it can and sometimes does extend too close to the joint surface, thus causing arthritis. It may actually penetrate the hip joint, thus making motion impossible and rendering it impossible to get the patient in a chair to encourage motion without pain. Also, where the nail is too long the same will destroy a portion of the hip socket.

If the nail inserted is too short, it would have to be extracted and a longer nail inserted. It is obvious that such a procedure would diminish the stability or security of fixation of the nail in the hip.

It is therefore the primary object of my invention to enable a, nail of the proper length to be selected and in this connection, Iemploy sectional adapters for association with a Smith- Peterson nail. The sectional adapters being of varying lengths to permit the one of the proper length to be selected and secured to the head of the nail, or to enable several adapter units to be added to the nail.

' In determining the length of nail to be used, the surgeon simply holds a Smith-Peterson nail in front of an X-ray photograph or film of the fractured femur and in this manner the proper length of the nail to be used can be selected.

Other objects and advantages of the invention will become apparent from the following description, when taken into consideration with the accompanying drawing.

In the drawing, forming a part of this specification, andin which like reference characters designate corresponding parts. throu h t e Several views:

Figure 1 is a side elevation showing the Smith- Peterson nail with my adapter unit associated therewith in position for fixation of a fracture of the neck of the femur.

Figure 2 is an enlarged fragmentary sectional view through the head of the nail showing one of the adapters secured thereon.

Figure 3 is a perspective view showing the Smith-Peterson nail and one of the adapter units disconnected from the head of the nail.

Figure 4 is an enlarged detailed view, partly in section of a smaller length adapter unit.

Figure 5 is a sectional view through a fractured femur showing the conventional Smith-Peterson nail inserted therein, and

Figure 6 is a similar view illustrating my adapter with the fracture nail positioned therein.

In the drawing, I have illustrated the fractured femur generally by the numeral l, the same comprising the head 2, the neck 3, and the shaft 4. When fractures of the femur occur, they usually occur either across the neck 3 or in the intertrochanteric area the angle of such breaks being variable.

The conventional Smith-Peterson nail commonly used in connection with the internal fixation of such fractures is shown generally at 5 in Figure 5. This nail isv cannulated, although a non-cannulated nail may be used. The nail comprises a shaft having usually three longitudinal and radial fins 6, a sharpened forward edge 1 and a head 8, that is substantially cylindrical. The head of the nail is formed with the threaded socket 9 and the outer face ll] of the socket is fiat.

Adapter units ll of varying lengths form a salient part of this invention for cooperation with the head of the facture nail. These adapter units are all of the same diameter and the diameter of the body of each adapter unit is the same as the diameter of the cylindrical head 8 of the nail, as clearly shown in the drawing. The adape ter units may be formed of stainless steel or of any other suitable metal.

Each adapter unit ll includes a cylindrical body I2 from the forward end of which extends a threaded stud [3 while an internally threaded socket I4 is formed in the rear end of the body. It will also be noted that the threaded sockets of both the nail and the adapter units are of the same size and that the threaded stud formed on the forward end of each adapter unit is adapted to be screwed into the threaded socket in the head of the nail, with the adjacent fiat faces of the head and adapter unit abutting each other. This is clearly shown in Figure 2 of the drawing.

Longitudinally extending flutes 15 are formed completely around the body 12 of each adapter unit to insure proper securement of the adapter unit in the femur against rotation and displacement when the nail and adapter unit connected thereto are driven into the femur and the cortex of the latter.

With my improved device, there is never any necessity for selecting a nail which is too long. If the nail is too short, the surgeon simply adds the appropriate adapter unit to the head of the nail and drives it into the hip, thus forming a longer nail and obviating the necessity of having to remove or extract a nail that was initially too short.

With my invention, no calculations areneces sary. The surgeon simply holds a Smith-Peterlength of nail which, in'the X-ray film reaches from the point-where the guide wireenters the cortex to a point just barely beyond the fracture line.

Such nail cannot possibly be too long, since there is at least an inch and a quarter of distance from the fracture to the surface of the head of the femur, and in no instance is there suflicient impaction or distortion due tothe' enlargement of the image on the X-ray film or sliding-.of the nail upward during insertion of sufficient magnitude to cause such a nail to be too long.

In some instances, a nail selected by this procedure,. so that it reaches just beyond the fracture line on the X-ray film, will be of the proper length.

In case the X-raycheck-up, which is taken on the operating table after thenail has been inserted, indicates that the nail does not penetrate far enough into the head of the femur, one of my adapter units of the proper length is selected and its stud is threaded into thethreaded socket of the Smith-Peterson nail and then the nail and attached adapter are driven further into the femur.

With my construction one or more unitsmay be attached to the head of the nail. to produce the desired length. Also, in cases of. inter-trochanteric fractures, Thornton" plates can be attached to my adapter.

While I have shown the preferred embodiment of my invention, it is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention and the scope of the appended claims.

Having thus described my invention, what I claim is:

1. A fracture fixation member comprising in combination, a fracture nail having an. internal socket formed in its head, and a nail extension adapter unit disposed against the rear end of the head of the nail, said adapter unit having a stud on .its forward end engaging within the socket in said head, said adapter unit being substantially of the same diameter as the head of the fracture nail and coaxial therewith and intended to enter the bone along with the nail.

2.A fracture fixation member comprising in combination, a fracture nail having an internal .4 socket formed in its head, and a nail extension adapter unit disposed against the rear end of the head of the nail, said adapter unit having a stud on its forward end engaging within the socket in said head, said adapter unit being substantially of the same diameter as the head of the fracture nail and coaxial therewith and intended to enter the bone along with the nail, the body of the adapter. unit being fluted longitudinally to secure the same against rotation in the bone.

3. A fracture fixation member comprising in combination, a fracture nail having a cylindrical being flat, an internally threaded socket formed in-said head, a nail extension cylindrical adapter unit having a flat front face disposed against the flat'face'of the head, a threaded stud extending fromtheforward end of the adapter unit threadedly engaging the socket of the head and securing the adapter unit coaxially tothe rear end of the nail, the body "of the adapter-unit'being of substantially the samediameter as the nail and intended to enter the .bone along with the nail. 4. A fracture fixation member comprising in combination, a fracture nail having a cylindrical head on its rear end, the rear face of said head being flat, an internally threaded socket formed in said head, a nail extension cylindrical adapter unit having a fiat front face disposed against the flat face of the head, a threaded stud extending from the forward end of the adapter unit threadedly engaging the socket of the head and securing the adapter unit coaxially'tothe rear end of the nail, the body of the adapter unit being of substantially the same diameter as the nail and intended to enter the bone along with the nail, said adapter unit being of a predetermined length.

5. A fracture fixation member. comprising in combination, a fracture nail having a cylindrical head on its rear end, the rear faceof said head being fiat, an internally threaded. socket formed in said head, a nail extension cylindrical adapter unit having a flat front face disposed against the flat face of the head, a threaded stud extending from the forward end .of the adapter unit.threadedly engaging the socket of thexhead and securing the adapter unit coaxially to the rear end of thenaiLthe body of the adapter unit being of substantially the same diameter as the nail and intended to enter the bone along with the nail, the rear end of the adapter unit having a threaded socket for receiving an additional adapter unit, when a longer nail is to be used.

ALLEN S. LLO

REFERENCES CITED The-following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,187,852 Friddle June 23, 1940 2,439,995 Thrailkill Apr. 20, 1948 FOREIGN PATENTS Number Country I I Date I I 4,554 Great Britain Mar. 24, 1888 of 1888 

